Fiber mat forming hood with movable side walls

ABSTRACT

A HOOD FOR PRODUCING GLASS FIBER BATTS AND THE LIKE HAVING A PRESSURE BALANCE CHAMBER BETWEEN THE MOVABLE SIDE WALLS AND THE PRODUCT CONVEYOR.

FIBER MAT FORMING HOOD WITH MOVABLE SIDE WALLS Filed April 1, 1969 A. B. HAVENS June 1,1971

4 Sheets-Sheet 1 Q9503 fizziw $2 Mk 5 5% E245 zozmqfiw Y INVENTORL JPN/we fl/ m/ A. B. HAVENS June 1, "1 971 FIBER MAT FORMING HOOD WITH MOVABLE SIDE WALL$ Filed April 1, 1969 4 Sheets-Sheet z INVENTOR. Jen/0 6. HAVf/VS June 1, 1971 V 3, 5 3,582,432

FIBER MAT FORMING HOOD WITH MOVABLE SIDE WALLS Filed April 1, 1969 4 Sheets-Sheet 3 K) 1257 3 I 1 f as j! y W 92; H

' if {a 92 .92 g; 65 6% 5i x 3 1/ "Il 7 ,O L 1 ya? [4 {I INVENTOR.

June 1,1971 v v s v 3,582,432

I. FIBER MAT FORMING HOOD WITH MOVABLE SIDE WALLS Filed 1 1 11.11, 1969 4 Sheets-Sheet 4 a 1 5 'li i 55 //z nvlwmA O INVENTOR.

.rwrmuvrws United States Patent US. Cl. 156 381 Claims ABSTRACT OF THE DISCLOSURE A hood for producing glass fiber batts and the like having a pressure balance chamber between the movable side walls and the product conveyor.

BACKGROUND OF THE INVENTION The conventional hood used for forming batts and mats of glass fibers comprises a foraminous product conveyor having a suction box located beneath the portion that receives the fibers from the fiber forming apparatus. The structure further comprises a hood structure having stationary walls which surround the portion of the product conveyor that is above the suction box and which receives the fibers. Aqueous solutions of organic binders are sprayed onto the fibers as they are deposited into the forming hood, and after a period of time, a layer of the binder and fibers builds up on the surfaces of the forming hood to a degree requiring the equipment to be taken out of operation and the deposits removed from the hood surfaces.

It has been desired to replace the stationary side wall portions of the hood with movable curtain walls which can be moved out of the forming area and cleaned While the forming hood is in operation, The prior art has not developed a sealing structure for closing off the space between the movable curtain walls and product conveyor which will prevent the side edges of the batt from being forced under the curtain walls where they become soggy with water and thereafter gum up subsequent process equipment. The sealing problem is made difficult in that the tops of the individual flights of the product conveyor have slightly different heights, and move up and down as they advance across the forming hood. In addition, the bottoms of the flights of the curtain Walls are not spaced uniformly from the product conveyor and the flights move laterally back and forth as they transverse the length of the forming hood. What is more, uneven Wear of the support structure for both the curtain Walls and the product conveyor increases this flight movement. This lateral back and forth movement of the curtain Walls against the side edge of the batts compacts the fibers into any clearance between the curtain walls and product conveyor as well as against any sealing structure that may be provided.

An object of the present invention is the provision of a new and improved hood structure that is sealed between the curtain walls and the product conveyor in such manner as to resist the working of the fibers underneath the sealing structure.

A further object of the present invention is the provision of a new and improved forming hood of the above described type which prevents the suction pan from drawing appreciable amounts of air into the suction pan from areas outside of the forming hood, and which does not produce an appreciable amount of drag upon the product conveyor.

Further objects and advantages of the invention will become apparent to those skilled in the art to which it relates from the following description, and the attached drawings.

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SUMMARY The fibrous batt forming hood of the present invention comprises a pair of opposing curtain walls which are positioned over the product conveyor and the lateral position of which can be adjusted towards and away from each other to produce various widths of batt. Plank-like structures having an appreciable thickness are p sitioned outwardly of the opposing adjacent runs of the curtain walls, which plank-like structures are arranged to overlie the product conveyor and restrict flow of air through those portions of the product conveyor outwardly of the adjusted position of the curtain walls. The bottom ends of the flights of the curtain walls terminate in outwardly projecting lips which terminate adjacent a face of the planklike structure, and which are spaced vertically from the product conveyor to form a pressure balance chamber. Strips of flexible sealing material extend downwardly from these lower lips in line with the inner smooth face of the flights, and into engagement with the top surface of the product conveyor. A clearance is provided between the projecting end of the lower lips of the flights, and the plank-like structures to provide an orifice through which air is drawn into the balancing chamber by the partial vacuum in the suction pan that is positioned below the product conveyor. It has been found that the compaction of the batt that is produced against the sealing strip is analogous to a tamping action of sand into a mold, in that the wedging action against the seal tends to build up and be retained, each time that the flights are forced against the batt. In the construction of the present invention, the lateral movement of the flights against the batt of fibers, increases the clearance between the plank-like structure and the projecting end of the lower lip of the flight to automatically increase the pressure within the balance chamber and thereby hold the seal rigid and force it against the batt, rather than be bent inwardly by the compaction pressure of the batt. A reversed tamping action thereby tends to be created to incrementally push back the fibers to counteract each increment of compaction pressure of the fibers against the seal.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an isometric view showing the general arrangement of apparatus embodying principles of the present invention;

'FIG. 2 is a fragmentary plan view, with portions broken away, of the movable side wall structure shown in FIG. 1;

FIG. 3 is a fragmentary sectional view taken approxi mately on the line 33 of FIG. 2;

FIG. 4 is a fragmentary sectional view taken approximately on the line 44 of FIG. 2;

FIG. 5 is an enlarged fragmentary view taken approximately on the line 55 of FIG. 3;

FIG. 6 is an enlarged fragmentary view of the sealing structure shown in FIG. 4;

FIG. 7 is a fragmentary view, similar to FIG. 6, but showing another embodiment of the invention; and

FIG. 8 is generally similar to FIG. 7, but showing still another embodiment of the invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The apparatus shown in the drawings for producing batt generally comprises a glass furnace 10 having a forehearth 12 proceeding therefrom to deliver the molten glass to a plurality of forming stations 14, one of which is shown in solid lines and others of which are shown by dotted lines. The bottom of the forehearth at each forming station is provided with a metal plate 16 having a hole therein for delivering a stream of molten glass 18 into the hollow shaft of a motor driven centrifuge 22. A motor 24 surrounds the top end of the shaft 20 and a centrifuge basket 26 having a plurality of openings in its outer periphery is fixed to the bottom end of the hollow shaft 20. A plurality of molten streams of glass are thrown from the openings in the basket 26, and a downwardly flow of gases over the edge of the basket 26, produced by means not shown, causes the molten streams of glass to be attenuated into small filaments that are dispersed in the stream of gases in what are known as a veil 28. The apparatus preferably includes a multiplicity of veil producing mechanisms 14 and four are shown in FIG. 1.

The glass fibers from the various veils 28 are collected on the top foraminous run 30 of a horizontal conveyor 32 having a head pulley 34 and tail pulley 36. A suction box 38 is positioned beneath the top run 30 to draw the large volume of gas downwardly through the top run 30 and cause the fibers of the veils to be deposited on the top surface of the conveyor 32 in the form of a mat 40. The swirling volume of gases and fibers which constitute the veils do not assume the cylindrical shape shown in the drawings, but spread out violently in all directions and must be confined to the top surface of the conveyor 32. In the embodiment shown, the fibers and gases are confined to the top run 30 by a pair of parallel side walls 42, a stationary rear end wall 44, a front end wall 46, and roll gate 48.

The mat of loose fibers that is formed witthin the confines of the walls above described (hereafter called forming hood), is bonded together by a binder that is sprayed into the confines of the forming hood through a plurality of nozzles 50. The binder that is used is an aqueous solution which permeates the mat. Droplets of the binder solution are held at crossover points of the fibers forming the mat, and the binder impregnated mat 40 is delivered to a cure oven 52 where the water is removed and the binder cured to a thermoset condition. In the present instance, the binder which is used is a phenol formalde hyde resite. The bottom edge of the front end wall 46 is positioned well above the height of the fibers collected in the forming hood, and the rear edge of the roll gate 48 is generally tangent to the bottom edge of the front end wall 46 to generally seal off the forming hood and smoothen out the fibers issuing from the forming hood.

In the present instance, the parallel side walls 42 are formed as part of endless conveyors 54, the adjacent parallel runs 42 of which move in the same direction as the top run 30 of the horizontal conveyor 32 but at approximately one-half the speed. As such, the movable side walls 42 rub against the side edges of the mat being produced, but it has been found not to tear or unduly damage the side edges of the mat.

Each of the endless side wall conveyros 54 are formed from a plurality of vertical elements 56 which are fastened to and are carried by top 58 and bottom 60 roller chains which move about sprockets forming tail pulleys 62 and head pulleys 64. The sprockets forming each head pulley 64 are connected together by a shaft 66 and each shaft 66 is in turn driven by a motor and gear reducer 68, only one of which is shown. The endless side wall conveyors 54 are constructed in such a way that the space between the vertical conveyor elements open up, or become enlarged as they round the head pulley 64 to loosen and expose any debris accumulated therein. The debris between the vertical conveyor elements is washed from the side wall conveyors by wash nozzles 70 which project a stream of water against the top edge of the respective side wall conveyor outwardly of the end wall 44 as the vertical elements round the head pulley 64. The flow of wash water issuing from the nozzle 70 washes wads and other debris downwardly into a recovery pan 72 from which the wash water flows to a separator 74 which removes the glass fibers. The wash water is recirculated by a wash water pump 76 to the nozzles 70. The binder that is removed from the wads and from the side walls becomes dissolved in the wash water and a side stream of the wash water is pumped by pump 78 to a binder preparation tank 80 where it is used to formulate the aqueous binder solution. The aqueous binder solution is in turn pumped by pump 82 to the binder nozzles 50 previously described. After the vertical conveyor elements are washed by the flow of water from the nozzles 70, the vertical elements move forwardly to a squeegee 84 positioned at an angle to force the water downwardly into the recovery pan 72. The squeegee 84 is located adjacent the head pulley 64 and any water that remains after the squeegee operation, has an appreciable time to evaporate before the elements round the tail pulley to move into position in the forming hood.

As previously indicated, the adjacent movable side walls 42 of the forming hood each comprise one run of identical but opposite hand endless conveyors 54. Each of the vertical flights 56 are removably fastened at their upper edge to the top roller chain 58 as by bolts 86. The lower links of the top roller chain 58 are provided with intergral depending brackets 88 to which the flights 56 are bolted. Alternate ones of the flights 56 are provided with horizontal axles 90 on which support rollers 92 are journaled and which in turn ride upon longitudinally extending rails 94 which extends lengthwise of the horizontal conveyor 30. The flights 56 having these support rollers 92 thereon therefore support the top roller chain 58, and the top roller chain 58, in turn, supports the alternate flights 56 which are positioned between the flights 56, having the rollers 92 thereon. The top roller chain 58 rides between opposing parallel guide surfaces 96 that are supported by suitable brackets 98.

The vertical flights 56 which do not contain a support roller 92 are provided with an upwardly extending guide 100 adjacent their lower end. Each upwardly extending guide comprises a roller 102 supported by a vertical axle 104 that is in turn supported by an angle bracket 106 aflixed to the flight 56. The rollers 102 are positioned between opposing parallel vertical guide surfaces 108 which parallel to the guide surfaces 96. In the preferred embodiment shown in the drawings, the guide surfaces 108 are the depending legs of an inverted U-shaped member 110 which keeps debris out of and protects the upwardly extending guides 100.

The lower end of the vertical flights 56 are moved in unison with their upper ends by means of the bottom chain 60 which as previously explained is driven by a shaft 66 which also drives the upper roller chain 58. The bottom roller chain 60 is secured to the lower portion of each of the vertical flights 56 by quick disconnect means 112 which securely clamps the chain to each of the flights. In the present instance, the quick disconnect means 112 comprises a generally horizontal Z-shaped bracket or dog 114, the downwardly depending leg of which is welded to the conveyor flight, and the upper extending leg 118 of which confines a conveyor link bracket 120 between itself and the surface of the conveyor flight. The conveyor link brackets 120 are integral with a link of the roller chain 60 and each has a U-shaped slot or notch 122 in its end surface, which notch 122 receives the horizontal leg 124 of the Z-shaped bracket 114. The side edges of the notch 122 therefore, bear against the sides of the Z- shaped dog 114 to drive the lower end of the flight 56 connected thereto. The conveyor link brackets 120 which are connected to the flights 56 having upwardly extending guides 100 thereon, project downwardly from the roller chain 60 for reasons which will later be apparent. The conveyor link brackets 120 which are affixed to the flights 56 having a support roller 92 thereon, extend upwardly from the roller chain 60 for reasons which will likewise later be apparent. Lateral movement of the bottom end of alternate flights 56 is therefore directly prevented by the guides 100, and the flights in turn prevent lateral movement of the conveyor chain 60. The lower ends of the remaining flight 56, which do not contain an upwardly extending guide 100, are restrained against lateral movement by the conveyor chain 60.

When it is desired to remove a conveyor flight 56 having a support roller 92 thereon, its bolts 86 is removed from the top chain 58, and the flight 56 is lifted vertically to slide the Z-shaped bracket 114 out of the notch 122 in the conveyor link bracket 120 of the lower roller chain 60. No other attachment means is provided to an adjacent conveyor flight 56. The conveyor flight 56 having a vertical guide 100 thereon, is removed by first removing its bolt 86, followed by downward movement of the flight 56 relative to the rest of the structure. Downward movement of the flight moves its Z-shaped bracket 114 out of the slot 122 in the cooperating conveyor link bracket 120, and at the same time slides the upwardly extending guide 100 out of the U-shaped guide member 110.

The forward and return runs of each endless conveyor 54 are supported and guided by structure which is identical excepting that it is opposite hand. The rails 94, brackets 98 and U-shaped members 110 are supported by a truss structure 126 that is centrally located between the runs of the conveyor 56 and which extends between the head pulley 64 and tail pulley 62. Opposite ends of each truss structure 126 are provided with a horizontal carriage 128 having flanged wheels 130 at its opposite ends, and which flanged wheels ride upon horizontal rails 132 which are positioned laterally over the horizontal conveyor 30. Each endless conveyor 54, therefore, can be positioned laterally with respect to the horizontal conveyor 30 to adjust the width of the mat which is formed thereon. Additionally, the endless conveyors 54 can be moved laterally to a position free and clear of the horizontal conveyor structure 30 where the conveyor flights 56 can be moved downwardly as is required for the removal of those flights having an upwardly extending guide 100.

The bottom ends of the flights 56 are positioned approximately 1 inch above the top surface of the horizontal conveyor 30 to provide a pressure balancing chamber as 'will now be described. In the preferred embodiment, the flights 56 are pan shaped so that all four sides are turned over, and so that the bottom edge is provided with a horizontally outwardly extending lip 134 that is approximately 1 inch long. A plank-like structure 136 approximately 1% inches thick is supported by a suitable bracket 138 from the support structure 126 outwardly from the lips 134 of the inner run of the curtain wall 42 approximately of an inch above the nominal top surface of the product conveyor 32. The plank-like structure 136 extends laterally by a distance greater than the lateral adjustment of the curtain walls 42, so that the plank-like structure 136 will at all times overlie and generally seal oil? the portion of the product conveyor which is laterally outwardly of the inner run of the movable side walls 42. The lips 134, plank-like structure 136, and product conveyor 32 form three sides of a pressure balancing chamber 140. The other wall of the balance chamber 140 is formed by strips 142 of flexible sealing material which extends from the lips 134 downwardly into engagement with the product conveyor 32, and the inner face of which is coplanar with the inner face of the flights 56. The strips 142 are slightly larger than the width of the flight 56, so that they abut each other to form a continuous seal. The sealing strips 142 are made of a tough flexible material such as neoprene rubber, silicone rubber, or a polyurethane rubber, so that they will bend and flex out of the way rather than bind or tear when abutted by a high flight of the product conveyor 140. In the preferred embodiment shown in the drawing, the sealing strips 142 are angularly shaped with one leg suitably bolted or otherwise fastened to the lip 134. In the embodiment shown, a thin metal strip 144 is positioned beneath the leg of the seal and the leg is clamped between the metal strip and lip by means of rivets 146.

According to the invention, it has been found that the batt being formed exerts a growing force against the side walls which causes the batt to follow the slight lateral in and out movement of the flights 56, to produce a tamping action which tends to work the fibers under the sealing strips 142. This tamping action is opposed as will now be described. When a sidewall flight moves laterally inwardly against the batt, the lip 134 simultaneously moves away from the plank-like structure 136 to increase the gap therebetween, and thereby reduce the restriction to the air flow being drawn into the balancing chamber 140 by reason of the suction beneath the product conveyor 32. The resulting increase in air flow increases the pressure within the balance chamber 140, which in turn increases the pressure against the sealing strip 142, to force it outwardly against the batt at the same time that the flight 56 is moving against the batt. This increased lateral movement pushes the edge of the batt away uniformly. When the flight 56 moves outwardly, the distance between the lip 134 and the board 136 is decreased, so that the vacuum in the chamber 140 is increased to pull the seal back to its original position. There is, therefore, provided a reverse tamping action against the side of the batt which tamps it back out away from the flights to keep the fibers from working under the seal. The plank-like structures 136 shown in the drawing are, in fact, wood planks.

The embodiment shown in FIG. 7 is generally similar to that previously described, but differs therefrom in that the movable wall structure 42a is made of a continuous flexible sheet material, as for example stainless steel, or a fibrous reinforced plastic belt material. In addition, the embodiment of FIG. 7 may use a pan-shaped longitudinal member 136a which has a plastic surface. Those portions of the embodiment shown in FIG. 7 which correspond to portions of the embodiment previously described, are designated by a like reference numeral characterized further in that a suflix a is aflixed thereto.

In a specific arrangement of the embodiment shown in FIG. 7, the movable wall structure 42a is made of stainless steel and does not contain a horizontal lip 134. In place thereof, the sealing strip 142a is caused to include a vertical leg 148 which extends upwardly from the horizontal leg 150, and the innerface of which is recessed as at 152 so that it fits against the back side of the stainless steel strip 42a so that the innerface of the stainless steel 42a is flush with the innersurface of the bottom leg of the strip 42a. The vertical leg 148 is riveted to the stainless steel curtain wall, as by the counter sunk rivets 146a and the horizontal leg 150 extends toward the longitudinal member 136a to control the air flow therebetween into the balance chamber 140a. The longitudinal member 136a is made of sheet steel, the out surface of which is coated with an epoxy resin, or other nonscufling plastic.

The embodiment shown in FIG. 8 is generally the same as that shown in FIG. 7, excepting that the horizontal leg of the plastic strip 14212 is reinforced by a relatively stiif angular strip 154. Those portions of the embodiment shown in FIG. 8 which correspond to the portions of the embodiment shown in FIG. 7 are designated by a like reference numeral characterized further in that a suflix b is aflixed thereto. The arrangement of FIG. 8 provides a slightly different tamping action to the side edges of the mat being formed, which may be beneficial in some instances.

While the invention has been described in considerable detail, I do not wish to be limited to the particular embodiments shown and described, and it is my intention to cover hereby all novel adaptations, modifications, and arrangements thereof which come within the practice of those skilled in the art to which the invention relates.

I claim:

1. In a fibrous pack forming facility: means for distributing fibers over a foraminous advancing collection surface, a movable curtain wall structure extending generally vertically from one major surface of said collection surface and comprising a plurality of pan shaped flights having aligned generally fiat backs and end lips which project in one lateral direction from said backs and which lips are spaced from said one major surface of said collection surface, means for drawing air through said collection surface, a longitudinal member substantially thicker than said lips positioned in said one lateral direction from said lips and overlying a portion of said advancing collection surface to restrict air flow through said portion of said collection surface, and strips of flexible material arranged end to end flush with the flat backs of said flights beneath said end lips to form a pressure balance chamber bounded by said strips, lips, longitudinal member and foraminous collection surface.

2. The fibrous pack forming facility of claim 1 wherein said longitudinal member is held fixed and generally spaced apart from said advancing collection surface.

3. The fibrous pack forming facility of claim 2 wherein said longitudinal member is wood.

4. The fibrous pack forming facility of claim 1 wherein the ends of each flexible strip is generally coterminous with ends of a lip and each strip has a right angle portion fastened to the bottom of the lip.

5. The fibrous pack forming facility of claim 4 wherein said flexible strips are of a material from the group consisting of a neoprene rubber, a silicone rubber, and a polyurethane rubber.

6. In a fibrous pack forming facility: means for distributing fibers over a foraminous advancing collection surface, a movable curtain wall structure extending generally vertically from one major surface of said collection surface and positioned laterally outwardly of said means for confining fibers from said means to said collection surface, means for drawing air through said collection surface, a longitudinally extending member positioned over said collection surface laterally outwardly of said curtain wall structure, said member having a generally vertical side surface that parallels said curtain wall structure, and an anguarly shaped strip of flexible material fastened to the bottom of said curtain wall structure with one leg extending toward said collection surface and the other leg extending toward said vertical side surface of said longitudinal member to form a pressure balance chamber.

7. The fibrous pack forming facility of claim 6 wherein the portion of said movable curtain wall structure adjacent said collection surface is a thin vertical strip, and said angularly shaped strip of flexible material has a T configuration with one leg fastened to said vertical strip of said curtain Wall structure.

8. The fibrous pack forming facility of claim 7 wherein the respective legs of said angularly shaped strips which extend toward said longitudinal member and said collection surface, are stiffened to move integrally relative to the leg secured to the curtain Wall structure.

9. The fibrous pack forming facility of claim 7 wherein said flexible strip is made of a material from the group consisting of a neoprene rubber, silicone rubber, and a polyurethane rubber.

10. The fibrous pack forming facility of claim 7 wherein said longitudinal member is held fixed and generally spaced apart from said advancing collection surface.

References Cited UNITED STATES PATENTS 9/1960 Francis, Ir. 156-377X 8/1961 Morrison et a1. 156-381X US. Cl. X.R. 156-377 

